1. Field of the Invention
The present invention relates to a display control apparatus for displaying image data on a display device.
2. Description of the Related Art
In general, an image pickup apparatus, e.g., a digital camera, includes a liquid crystal display (LCD) panel and a video output terminal for outputting a video signal. The image pickup apparatus can display a photographed image on the LCD panel or a television (TV) monitor connected with the video output terminal.
Further, the image pickup apparatus can display on-screen display (OSD) data on the LCD panel or the TV monitor by superimposing the data on the photographed image. The OSD data is, for example, character information such as shooting date and time of a photographed image and an icon showing an operation condition of an image pickup apparatus.
Shapes of a character and an icon are stored in a read only memory (ROM) as font data and make up the OSD data when the font data is read from ROM, corresponding to character information such as shooting date and time and an operation condition of an image pickup apparatus. In this case, it is desirable that the LCD panel and the TV monitor use the same font data in order to reduce the capacity of ROM.
An aspect ratio of a LCD panel and a TV monitor is conventionally 4:3, however, recently, a wide screen having an aspect ratio of 16:9 is widely used as a TV monitor. Further, an image pickup apparatus including an LCD panel having the aspect ratio of 16:9 is also commercialized.
In the context of the present specification, an LCD panel and a TV monitor, which have the aspect ratio of 4:3, will be respectively referred to as “a normal LCD” and “a normal TV”. Further, a LCD panel and a TV monitor, which have the aspect ratio of 16:9, will be respectively referred to as “a wide LCD” and “a wide TV”.
Japanese Patent Application Laid-Open No. 2002-305752 discusses an image signal processing apparatus which resizes image data obtained from an image sensor to a display size of a TV monitor and generates display data to display the resized image data on a LCD panel.
With respect to a digital camera including a wide LCD, Japanese Patent Application Laid-Open No. 2005-260740 discusses a method for mapping image data in a memory space corresponding to the aspect ratio of a TV monitor, a digital camera capable of switching a frequency of a clock signal, and an image signal generating method.
However, according to the conventional technology discussed in Japanese Patent Application Laid-Open No. 2002-305752, only a technique in which an LCD Panel and a TV monitor have the same aspect ratios is described and a technique in which the aspect ratios of an LCD panel and a TV monitor are different is not considered.
For example, in a case where a wide LCD and a normal TV are used, when the apparatus resizes image data to a display size of a normal TV having the aspect ratio of 4:3 and displays the resized image data on a wide LCD having the aspect ratio of 16:9, the wide LCD displays a horizontally enlarged image. FIGS. 6A to 6C illustrate examples of this case. FIG. 6A illustrates a resized image data, FIG. 6B illustrates the display on a normal TV, and FIG. 6C illustrates the display on a wide LCD. Although a normal TV displays a true circle image as illustrated in FIG. 6B, a wide LCD displays a horizontally enlarged ellipse image as illustrated in FIG. 6C.
In addition, OSD data has the same problem. That is, when an apparatus displays OSD data on a wide LCD having the aspect ratio of 16:9 using font data of a normal TV having the aspect ratio of 4:3, a character and an icon are horizontally enlarged, and thus they have poor viewability.
In order to address these problems, a technology using different font data in an LCD panel and a TV monitor can be considered, but there arises a new problem that a capacity of ROM for storing font data increases.
In addition, the conventional technology discussed in Japanese Patent Application Laid-Open No. 2005-260740 does not consider display of OSD data.